AutoCodes – Chevrolet – P18B7 2018 Chevrolet Silverado

P18B7 2018 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Shorted

Quick Answer

The internal mode switch indicates the Transmission Control Module (TCM) which gear position the vehicle operator has selected. Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P18B7 2018 Chevrolet Silverado indicates Internal Mode Switch 'C' Circuit Shorted.
Common causes: Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 250

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 23, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P18B7 2018 Chevrolet Silverado Description

The internal mode switch indicates the Transmission Control Module (TCM) which gear position the vehicle operator has selected. The internal mode switch consists of 5 separate hall effect switches. Each hall effect switch is supplied with a 9 V reference circuit and a signal circuit from the TCM. Each signal circuit for each gear selector position will have either a voltage reading of 0.70–0.96 V indicating On or 1.68–2.38 V indicating Off. The voltage values on each internal mode switch circuit will change and are dependent on the position of the gear selector. The state of each internal mode switch A/B/C/P/S signal circuit is displayed on the scan tool. The Diagnostic Trouble Code (DTC) will be set when the TCM has detected the internal mode switch C signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B7 2018 Chevrolet Silverado - Internal Mode Switch 'C' Circuit Shorted - AutoCodes.com — P18B7 2018 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B7 2018 Chevrolet Silverado?

Faulty Transmission Internal Mode Switch
Transmission Internal Mode Switch harness is open or shorted
Transmission Internal Mode Switch circuit poor electrical connection
Faulty Transmission Control Module (TCM)

How to Fix the DTC P18B7 2018 Chevrolet Silverado?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P18B7 2018 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P18B7 2018 Chevrolet Silverado code?

Need more information on how to fix the P18B7 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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Get the P18B7 2018 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P18B7 2018 Chevrolet Silverado Code

1. What are common symptoms of OBDII code P18B7 in a 2018 Chevrolet Silverado?

- Common symptoms include issues with shifting gears, the transmission not engaging properly, and the vehicle going into limp mode.

2. What does the OBDII code P18B7 'Internal Mode Switch C Circuit Shorted' mean for a 2018 Chevrolet Silverado?

- This code indicates a short circuit in the internal mode switch 'C' circuit of the transmission range sensor.

3. What are possible causes of OBDII code P18B7 in a 2018 Chevrolet Silverado?

- Causes may include a faulty internal mode switch, damaged wiring or connectors in the circuit, or issues with the transmission control module.

4. How can I diagnose the OBDII code P18B7 in my 2018 Chevrolet Silverado?

- Diagnosis typically involves using a scan tool to read the code, inspecting the internal mode switch and related components, and testing the circuit for shorts.

5. Can I still drive my 2018 Chevrolet Silverado with OBDII code P18B7?

- It is not recommended to drive the vehicle with this code as it can lead to transmission issues and potential safety hazards.

6. What are the repair options for OBDII code P18B7 in a 2018 Chevrolet Silverado?

- Repair options may include replacing the internal mode switch, repairing damaged wiring or connectors, or reprogramming the transmission control module.

7. Is it safe to reset the OBDII code P18B7 in my 2018 Chevrolet Silverado using a scan tool?

- While you can reset the code using a scan tool, it is crucial to address the underlying issue causing the code to prevent further damage to the transmission system.

8. Can a DIY enthusiast fix OBDII code P18B7 in a 2018 Chevrolet Silverado?

- Depending on the level of expertise, DIY enthusiasts may be able to diagnose and repair this code, but it is recommended to seek professional help for accurate diagnosis and proper repair.

9. How much does it cost to repair OBDII code P18B7 in a 2018 Chevrolet Silverado at a dealership?

- Repair costs can vary depending on the underlying issue, but it may involve parts replacement and labor charges, which can range from a few hundred to over a thousand dollars.

10. Are there any recalls or technical service bulletins related to OBDII code P18B7 in a 2018 Chevrolet Silverado?

- It's advisable to check with the dealership or manufacturer for any recalls or technical service bulletins related to this specific OBDII code to see if there are known issues or remedies available.